quarkus-langchain4j-demo

Langfuse Quarkus LangChain4J Demo Application

Prerequisites

• Java 21+
• Langfuse stack (Cloud or Self-Hosted)
• Langfuse API Keys
• An OpenAI Api Key

How to run

1. Configure environment variables to connect Spring AI demo app with Langfuse.

   export QUARKUS_LANGCHAIN4J_OPENAI_API_KEY=sk-xxx-...
   export QUARKUS_OTEL_EXPORTER_OTLP_ENDPOINT="https://cloud.langfuse.com/api/public/otel" # 🇪🇺 EU data region
   # export QUARKUS_OTEL_EXPORTER_OTLP_ENDPOINT="https://us.cloud.langfuse.com/api/public/otel" # 🇺🇸 US data region
   # export QUARKUS_OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:3000/api/public/otel" # 🏠 Local deployment (>= v3.22.0)
   export QUARKUS_OTEL_EXPORTER_OTLP_HEADERS="Authorization=Basic $(echo -n "pk-lf-xxx:sk-lf-xxx" | base64)"
   

2. Run the sample application via ./mvnw quarkus:dev.
3. Observe the new trace in the Langfuse web UI.